A conventional pneumatic-hydraulic riveter as shown in FIG. 1 includes an air cylinder A formed on a bottom portion of the riveter, a hydraulic section H secured to an upper portion of the air cylinder A, and a rivet pulling gun P formed on a top portion of the hydraulic section, whereby upon a triggering of the trigger T to open a compressed air inlet to drive a piston in the air cylinder A to drive a hydraulic plunger in the hydraulic section H to set a rivet onto a fastening object as retained on the jaws J held in the rivet-pulling gun P. However, after the rivet is set, the mandrel broken off from the rivet should be further removed from the gun P such as by inclinedly gravitationally drawing the spent mandrel downwardly rearwardly to be collected in the disposal collector D.
Hence, the conventional riveter has the following drawbacks:
1. The spent mandrel as broken off from the setting rivet is drawn by its gravity along the rearwardly sloping central through hole C in the gun P. The gun should be tilted to draw the mandrel outwardly to thereby reduce the setting rate for a riveting job.
2. The repeated clamping operations of rivet by the jaws J may produce burrs or scraps which will be accumulated on the jaw teeth, easily causing malfunction of the jaws (such as a poor clamping or sliding of rivet by the jaws) and requiring frequent maintenance jobs to clean the jaws.
3. In order to hold the rivet on a nosepiece (having jaws J therein) of the gun P, two hands should be simultaneously used to grasp the gun and hold the rivet, causing operation inconvenience.
It is therefore expected to invent a riveter through which a mandrel after setting will be automatically drawn outwardly and the burrs produced as clamped by the jaws will be purged or flushed for cleanliness.